High power diode lasers, typically utilizing bar and stacked array configurations, are capable of reliably producing in excess of hundreds of watts. In order to achieve these power levels, high drive currents are required. Unfortunately as a result of these drive currents, the failure of an individual diode laser can often lead to the catastrophic failure of an entire diode laser bar or array. Additionally, diode laser failure can damage other system components such as optical elements, electrical components and cooling systems that are in proximity to the defective laser.
At the end of a high power diode laser's operational life, any of a number of events may occur. For example, the diode laser can begin to de-laminate, de-bond, or simply crack. In addition to damaging adjacent diode lasers, these events can also lead to localized component melting and/or coolant leaks, the latter of which can have far reaching effects as the leaking coolant falls on other system components. Thus the failure of a single diode laser can lead to extensive system damage.
U.S. Pat. No. 6,028,878 discloses a technique which attempts to overcome one cause of diode laser failure, specifically current and voltage spikes. After noting that the current and voltage spikes (or surges) caused by power supply malfunctions and/or electrostatic forces can degrade the performance of a diode laser, the patent discloses fabricating a reverse diode laser bar along with the fabrication of the diode laser bar, the two bars sharing contact pads. As a result of this arrangement, the reverse diode laser bar provides surge protection for the corresponding diode laser bar.
Although the prior art discloses techniques for protecting a diode laser from voltage and current spikes, the prior art techniques do not provide protection to either adjacent diode lasers or system components that can be damaged when a diode laser undergoes catastrophic failure. The present invention overcomes these shortcomings.